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a story about a 1 rad that goes bang in the night!

SBoston Member Posts: 61

I have worked out most of the kinks in my 1 pipe system (with the help of Dan's books) and this website.  For the most part the system is quite with the exception of this pesky radiator that swooshes, ticks and clanks. As luck would have it, it's the radiator in my daughters bedroom (which she now believes is a monster behind that radiator cover).

At first I thought it was the pitch, so I repitched the radiator to a 1/4 bubble and have adjusted and readjusted. No luck. I then moved to the valve, I took the valve apart, repacked it and made sure nothing was obstructing the flow. I even filed down the little lip inside to made sure it had good flow. No luck. I took the old air value off and replace with an adjustable value to slow down the fill time. This helped, but it still clangs and swooshes. It doesn't leak and doesn't appear to be sagging anywhere.

I could use some help on this one. (FYI) it only clangs and swooshes in mid cycle. </span>


  • 4Barrel
    4Barrel Member Posts: 125
    take a look

    at pages 86-87 of Lost Art... perhaps the riser run out to this rad is not piped optimally.

    And/or the supply valve may not be open all the way (stuck), this constricts the space where the steam and condensate pass each other.

    I have a similar situation with one rad and am looking at these as possible causes.

    I'm sure there are other possibilities that the experienced folks here can comment on.

    Good Luck,

  • Problem radiator

    Hi- Where is the radiator located on the main? Near the end of the main farthest from the boiler?  You might try using a slower vent on the radiator and see if that helps.  Maybe Home Depot sells Monster Retardant. Reminds me of fond memories of my daughter when she was small. We had several resident monsters in our house.
  • SBoston
    SBoston Member Posts: 61
    Bad Rad

    This radiator is located on the second floor and happens to be the very last radiator on the main. The riser is piped the same as all the other rads in the house (1.5" steel), so it's hard believe that it could be that. To the untrained eye, the condensate is getting trapped in the radiator for some reason, but the more I pitched the radiator, the worse the problem seems to get.

    Can a radiator go bad?
  • Radiator

    Generally ,other than rusting out and /or leaking, radiators are pretty bullet proof.  They can sag in the middle which causes pooling of the condensate. You need to have the inlet valve fully open when operating the system. Otherwise the steam has to "duck down" under the partially closed valve and collides with the outgoing condensate (water) returning to the boiler.  The only way to slow the steam down is with a smaller capacity vent.

    When you had the radiator disconnected to work on the inlet valve did you clean out the inside? I'm just wondering that if you radically sloped the radiator whether it might have cause dirt / crud etc. to move to the intake end of the radiator and that might be causing a problem by blocking the condensate.

    Slope -  I know you have already checked this but make sure you radiator is properly sloped using a level. I had one that was visibly sloped but later found the house floor had sagged (old house!) and in fact the radiator was sloped the wrong way. You might also try different adjustments to the slope.  Start level and then add / stack  quarters one by one under each leg to increase the slope a little at at time and see if you can reach an optimum slope.

    I would try also different air vents. You mentioned that you were using an adjustable vent now -What brand is it?

    - Rod
  • Glen_7
    Glen_7 Member Posts: 82
    Same here

    I have a radiator with a similar problem. After trying everything, it is my belief that the horizontal runout from the riser to the valve does not pitch properly and that is where the water is collecting. It's possible it was installed marginally but worked ok until the house settled. The riser probably stayed the same height, being tied to the basement structure, and the second floor where the radiator is probably settled just enough to cause the problem. I would have had to rip up the oak floor and have the top half re-piped, so I decided to live with it.
  • SBoston
    SBoston Member Posts: 61
    Bad rad

    I actually decided to cut the rubber part of the valve off to see if it was a problem with the steam not able to pass by the condensate.  Again that didn't seem to help. I am going to try your suggestion with the quarters and see if that kind of fine adjustment works.
  • Big-Al_2
    Big-Al_2 Member Posts: 263
    edited October 2009
    Guitar Picks

    I had a radiator in my kitchen that would tick and clank loudly.  As it was heating up and cooling off, it was expanding and contracting.   Its little feet would aternately stick to the floor and then break loose as it changed size . . . making quite a racket.  I slipped a couple of slippery Delrin guitar picks under the feet on one end to stop them from sticking to the floor, and it fell silent.  If you're not a guitar player, then a couple of discs cut from a plastic milk jug might do the trick.  YMMV.
  • Expansion

    Good point Al !  A lot of creaking is from expansion and allowing the feet to slip a little could quiet things a lot. Under one of my radiators, the expansion / contraction over the years, has grooved the hardwood flooring. 
  • Jamie Hall
    Jamie Hall Member Posts: 19,968
    horizontal pipes

    A horizontal runout to the radiator, or any other horizontal piece on that radiator's feed, could very well be the problem.  I have one which did that, and it took a surprising amount of correction to the pitch to fix it.  Nor does it take all tha much length to create a problem -- any stretch of horizontal, even a few inches, could be your problem.

    And keep in mind that water hammer 'telegraphs' -- that is, the banging could be heard in the radiator, but could be coming from anywhere along the pipe.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • SBoston
    SBoston Member Posts: 61
    bad rad

    What about the swooshing in a radiator? What could cause that?
  • ttekushan_3
    ttekushan_3 Member Posts: 944
    whoosh 'n pitch.

    While you are experimenting with various styles and prices of shims (quarters, you know) you might try shimming the entire radiator upward. In other words, sometimes there is enough lift available in the pipe to raise it far enough to relieve a drainage issue. This has worked quite a few times for me.

    If this works, then you can make arrangements for the nipple coming up through the floor to be replaced with a shorter one.

    With regard to the whooooshing, the only time I've encountered this is in one of those old vertical pipe radiators about 125 years old. [Look in the Library section of this site under "Nason" radiators if you are curious of their layout. Quite elegant.] The lower chamber on those is wide open, but this two pipe radiator is at the very farthest end of the line, and was poorly pitched probably since WWI. Leveling it made matters worse. It had to be physically cleared/shoveled with a fashioned back-scratcher kind of device. That radiator is breathtakingly heavy and its way into the building was remodeled out somewhere around 1920 so it was cleaned in place. A really big wet vac really helped catch water and rust chunks.

    As such, you may have two problems, one being a horizontal not pitched enough, and the second being radiator debris resulting from decades of poor circulation caused by the first problem.

    Hope this helps.

  • HenryT
    HenryT Member Posts: 128
    bad rad

    hello. I've read from the above post that old and larger radiators may sag in the middle which causes condensate to pool in middle and bang when steam arrives.

    how do we fix this problem? assuming i have no clearance on the top to but in shim?

    the radiators fits exactly into a groove that is fitted for its size....

  • heatguy
    heatguy Member Posts: 102
    rad valve

    you say its a 1.5 riser pipe but you dont mention size of rad valve  if its 1"its no good, water and steam meet and make noise
  • Magnehelic
    Magnehelic Member Posts: 63

    Sterling......make sure that the horizontal runout hasn't been re-piped off the main with a 90 degree elbow......I ran into this last week in a house where someone had removed the rad and plugged off the piping, and when it got re-piped back in place, they used a 90 instead of a 45 for the runout.  bad deal.  By the way.....aren't you in Tenn anymore?  and if you are......where the heck did you find a house with steam heat?

    Don Smet
This discussion has been closed.